envsubst variant, using golang templates and Masterminds/sprig
$ envy
Usage: ./envy [opts] <template>...
-input string
<file> to render, defaults to first <template>
-output string
write output to <file> instead of stdout{{ range $host := splitList "," .hosts }}
{{- $host}} {{ index $ (print "hosts_" $host) }}
{{end}}
export hosts="front,back,db"
export hosts_front="192.168.42.1"
export hosts_back="192.168.42.2"
export hosts_db="192.168.42.3"
envy --output output.txt hosts.gotmpl
# or
envy --output output.txt --input hosts.gotmpl *.gotmpl
cat output.txt
# =>
front 192.168.42.1
back 192.168.42.2
db 192.168.42.3- Masterminds/sprig – Useful template functions for Go templates.
MIT © Michael Mayer